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6
Preparation
Installer reference guide
23
ERLQ004~008CA + 08S18CA3VF
Daikin Altherma low temperature split
4P3662261 – 2014.01
FHL1
FHL2
FHL3
M1
T1
M2
T2
M3
T3
f
d
c
b
a
f
g
h
e
a
Outdoor unit
b
Indoor unit
c
Heat exchanger
d
Backup heater
e
Pump
f
Shutoff valve
g
Collector (field supply)
h
Bypass valve (field supply)
FHL1...3
Floor heating loop (field supply)
T1...3
Individual room thermostat (optional)
M1...3
Individual motorised valve to control loop FHL1...3 (field
supply)
Maximum water volume
Use the following graph to determine the maximum water volume for
the calculated prepressure.
0.3
0.5
1
1.5
2
2.5
100
50
0
150
200
250
300
350
400
450
a
b
a
Prepressure (bar)
b
Maximum water volume (l)
Example: Maximum water volume and expansion vessel
pre-
pressure
Installation
height
difference
(a)
Water volume
≤280 l
>280 l
≤7 m
No prepressure
adjustment is required.
Do the following:
▪ Decrease
the
pre
pressure.
▪ Check if the water
volume
does
NOT
exceed the maximum
allowed water volume.
>7 m
Do the following:
▪ Increase
the
pre
pressure.
▪ Check if the water
volume
does
NOT
exceed the maximum
allowed water volume.
The expansion vessel of
the indoor unit is too
small for the installation.
In this case, it is
recommended to install
an extra vessel outside
the unit.
(a)
This is the height difference (m) between the highest point
of the water circuit and the indoor unit. If the indoor unit is
at the highest point of the installation, the installation height
is 0 m.
6.3.4
Changing the prepressure of the
expansion vessel
NOTICE
Only a licensed installer may adjust the prepressure of the
expansion vessel.
When changing the default prepressure of the expansion vessel
(1 bar) is required, take following guidelines into account:
▪ Only use dry nitrogen to set the expansion vessel prepressure.
▪ Inappropriate setting of the expansion vessel prepressure will
lead to malfunction of the system.
Changing the prepressure of the expansion vessel should be done
by releasing or increasing nitrogen pressure through the schräder
valve of the expansion vessel.
a
a
Schräder valve
6.3.5
To check the water volume: Examples
Example 1
The indoor unit is installed 5 m below the highest point in the water
circuit. The total water volume in the water circuit is 100 l.
No actions or adjustments are required.
Example 2
The indoor unit is installed at the highest point in the water circuit.
The total water volume in the water circuit is 350 l.
Actions:
▪ Because the total water volume (350 l) is more than the default
water volume (280 l), the prepressure must be decreased.
▪ The required prepressure is:
Pg = (0.3+(H/10)) bar = (0.3+(0/10)) bar=0.3 bar.
▪ The corresponding maximum water volume at 0.3 bar is 410 l.
(See the graph in the chapter above).
▪ Because 350 l is lower than 410 l, the expansion vessel is
appropriate for the installation.
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